I just changed the plugs,wires,cap and rotor on my 98 ram with a 5.9. They were original to the truck. Truck has 77k and the plugs looked great, but they were all gapped at .060-.065. The center electrode was clean, but worn/rounded on one side. Would the large gap be from being in there 15 years? They have never been out of the truck. I gapped them at .040 and used what came in the truck. Just wondering how the gap got so big.

Geo

 

Yes, plug gap will enlarge as the plugs wear. After 77,000 miles of use, not surprising to encounter a wider than stock gap.

 

If they are standard copper core plugs, they should be changed every 30k miles. The gap increases as they wear. Perfectly normal. Gap the new plugs properly and change every 30k.

 

That's what I thought, I just thought it was excessive. I changed everything. They still didn't look bad for 77k. The motor was run with moble1 since new. I bought it from the original owner in her mid 70's.

 

Read the plenum sticky before a couple of them don't look as good.

 

Heading to the sticky

 

Good call, although long(and has lots of useless posts in it. It has plenty of otherwise good info in it.

 

Zman17,

Read the sticky..I'm not having any issues listed. No oil use,no sark knock,tons of power on hills. What plugs do you think don't look good? They have been in there 77k miles. I'm going to look down in the butterfly's, I have to change the timing cover gasket. I will check it when it comes apart. Thanks for the help.

G

 

Replace your chain with a double roller! I bet your stock "chain" is already stretched

 

+1 on the double roller timing chain and gear set - Also, good to include a timing chain tensioner, too, as even double roller chain sets stretch over time and the tensioner will compensate for it. Here is a reference to the tensioner:

http://moparcarparts.com/P5007709-Ti...ar-Performance

FWIW, those plugs look great after going 77,000 miles. Looks like that motor is in pretty decent shape, based upon the looks of those plugs.